Steps:

1. Create a new user group
2. Create a new role
3. Assign this role to the group from step 1
4. Add a new policy to the role
5. Delete the policy
6. Delete the assignment

Actual result:

Assignment isn't removed. There is an error message: Could not find 'roleAssignment' with identifier '36'

Expected result:

Assignment is removed. Or if it's forbidden, error message should be more user friendly.